[en] Lockheed Martin Energy Systems, Inc. (LMES) operates the East Tennessee Technology Park (ETTP), formerly called the Oak Ridge K-25 Site, where uranium was enriched under contract with the US Department of Energy (DOE). Currently, ETTP missions include environmental management, waste management (WM), and the development of new technologies. As part of its WM mission, ETTP operates the TSCA (Toxic Substances Control Act) Incinerator (TSCAI) for treatment of hazardous waste and polychlorinated biphenyls (PCBs) contaminated with low-level radioactivity. Beginning in the autumn of 1995, employees from diverse ETTP buildings and departments reported experiencing headaches, fatigue, depression, muscle aches, sleeplessness, and muscle tremors. These symptoms were judged by a physician in the ETTP Health Services Department to be consistent with chronic exposures to hydrogen cyanide (HCN). The National Institute for Occupational Safety and Health (NIOSH) was called in to perform a health hazard evaluation to ascertain whether the employees' illnesses were in fact caused by occupational exposure to HCN. The NIOSH evaluation found no patterns for employees' reported symptoms with respect to work location or department. NIOSH also conducted a comprehensive air sampling study, which did not detect airborne cyanides at the ETTP. Employees, however, expressed concerns that the burning of nitrile-bearing wastes at the TSCAI might have produced HCN as a combustion product. Therefore, LMES and DOE established a multidisciplinary team (TSCAI Technical Review Team) to make a more detailed review of the possibility that combustion of nitrile-bearing wastes at the TSCAI might have either released nitriles or created HCN as a product of incomplete combustion (PIC)